1965 273 Intake Manifold Gaskets

I couldn't find a 273 four-barrel manifold so I installed an Edelbrock Performer 318 intake on my 273 using a 273 intake gasket. I checked with Edelbrock about the port size differences and was told that the turbulence caused by the port mismatch wouldn't be of any concern and could enhance combustion. The 318 manifold mating surfaces are the same as the 273, but the bolt hole's top surface has a different angle. I fabricated angled shims to apply the proper torque to seal the gasket. No vacuum leaks.